Change checkSourceLengthRule to use Span.IsWhiteSpace instead of Stri…#854
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…ng.Trim String.Trim can allocate a new string on each call, whereas Span.IsWhiteSpace() shouldn't allocate at all.
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@Numpsy argh, actually I realised that this PR makes allocations go down, but time go up? Do you mind changing it to use String.IsNullOrEmpty() instead? maybe it's the AsSpan() function that makes it a bit slower. |
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Sorry, I meant String.IsNullOrWhiteSpace() |
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Recent PR[1] changed this hot-path from `Trim().Length<>0`` to `AsSpan().IsWhiteSpace()` and while the latter allocates less, it took actually longer to execute according to the contributor's own benchmark analysis. Using String.IsNullOrWhiteSpace seems better here, because it shouldn't allocate either (vs `Trim()`) while it avoids calling `AsSpan()`, and the poor-man measurement stick I have so far is GitHub's CI runs: 3 jobs with the old codebase were slower than 1 job with this change. [1] fsprojects#854
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Recent PR[1] changed this hot-path from `Trim().Length<>0` to `AsSpan().IsWhiteSpace()` and while the latter allocates less, it took actually longer to execute according to the contributor's own benchmark analysis. Using String.IsNullOrWhiteSpace seems better here, because it shouldn't allocate either (vs `Trim()`) while it avoids calling `AsSpan()`, and the poor-man measurement stick I have so far is GitHub's CI runs: 3 jobs with the old codebase were slower than 1 job with this change. [1] fsprojects#854
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Tested it myself, and confirmed, it seems to be faster: #859 |
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Recent PR[1] changed this hot-path from `Trim().Length<>0` to `AsSpan().IsWhiteSpace()` and while the latter allocates less, it took actually longer to execute according to the contributor's own benchmark analysis. Using String.IsNullOrWhiteSpace seems better here, because it shouldn't allocate either (vs `Trim()`) while it avoids calling `AsSpan()`, and the poor-man measurement stick I have so far is GitHub's CI runs: 3 jobs with the old codebase were slower than 1 job with this change. [1] #854
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I thought at the time that the timing changes were within the reported margin of error, though this is probably something that can be effected by .NET version or platform as well. |
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…ng.Trim
String.Trim can allocate a new string on each call, whereas Span.IsWhiteSpace() shouldn't allocate at all.
Just a thought when looking at some Span related things.
If I run the existing benchmark app using the rule set which is enabled during the SelfCheck part of the CI build then I get this with the current code
And this afterwards
A small change improvement given the total allocations, but also a small change so I thought it'd still be useful.